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Log base 2

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Last updated date: 18th Apr 2024
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What are Logarithmic Functions?

  • A Logarithmic Function is a function that is the inverse of an exponential function.

  • The purpose of the logarithm is to tell us about the exponent.

  • Logarithmic Functions are used to explore the properties of exponential functions and are used to solve various exponential equations.

Log base 2 is an inverse representation of the power of 2. For example, n = bhere, n is a real positive number. And x is the exponent number. Then, the log base format of this is Logb n = x. 

 

Representation of a Logarithm Function

\[lo{g_a}b{\text{ }} = x,{\text{ }}then{\text{ }}{a^x} = b\]

 

What is Log Base 2 or Binary Logarithm?

  • Log base 2 is also known as binary logarithm.

  • It is denoted as (log2n).

  • Log base 2 or binary logarithm is the logarithm to the base 2.

  • It is the inverse function for the power of two functions.

  • Binary logarithm is the power to which the number 2 must be raised in order to obtain the value of n.

  • Here’s the general form.

 

\[{\mathbf{x}}{\text{ }} = {\text{ }}{\mathbf{lo}}{{\mathbf{g}}_{\mathbf{2}}}{\mathbf{n}}\;\;\;\boxed{} -  -  -  -  -  -  -  -  - \boxed{}{{\mathbf{2}}^{\mathbf{x}}} = {\text{ }}{\mathbf{n}}\]

 

 

Graph for Log Base 2

Properties of Log Base 2

There are a few properties of logarithm functions with base 2. They are listed in the table below.

Since we are discussing log base2, we will consider the base to be 2 here.

 

Basic Log Rules

Product Rule –

If the logarithm is given as a product of two numerals, then we can represent the logarithm as the addition of the logarithm of each of the numerals and vice versa.

\[lo{g_b}\left( {x{\text{ }} \times {\text{ }}y} \right){\text{ }} = {\text{ }}lo{g_b}x{\text{ }} + {\text{ }}lo{g_b}y\]

Quotient Rule –

If the logarithm is given as a ratio of two quantities, then it can be written as the difference of the logarithm of each of the numerals.

\[lo{g_b}\left( {\frac{x}{y}} \right)\; = {\text{ }}lo{g_b}x{\text{ }} - {\text{ }}lo{g_b}y\]

Power Rule -

If the logarithm is given in exponential form, then it can be written as exponent times the logarithm of the base.

\[logb({x^k}) = k{\text{ }}lo{g_b}x\]

Zero Rule –

If b is greater than 0, but not equal to 1. The logarithm of x= 1 can be written as 0.

\[lo{g_b}\left( 1 \right){\text{ }} = {\text{ }}0\]

Identity Rule –

When the value of the base b and the argument of the logarithm (inside the parenthesis) are equal then,

\[lo{g_b}\left( b \right){\text{ }} = {\text{ }}1\]

Log of Exponent Rule –

If the base of the exponent is equal to the base of the log then the logarithm of the exponential number is equal to the exponent.

\[lo{g_b}\left( {{b^k}} \right){\text{ }} = {\text{ }}k\]

Exponent of Log Rule –

Raising the logarithm of a number to its base is equal to the number.

\[{b^{logb\left( k \right)}} = k\]

 

Here are a Few Examples That show How the above Basic Rules work

Example 1 –

Log 40, which can be further written as,

Log (20× 2)

by-product rule 

= log 20 + log 2

which is equal to log 40

 

Example 2 – 

Find the value of log4(4)?

 logb(b) = 1, by identity rule

Therefore, log4(4) = 1.

 

The Formula for Change of Base

The logarithm can be in the form of log base e or log base 10 or any other bases. Here’s the general formula for change of base -

\[{\mathbf{Lo}}{{\mathbf{g}}_{\mathbf{b}}}\;{\mathbf{x}}{\text{ }} = {\text{ }}\frac{{{\mathbf{Lo}}{{\mathbf{g}}_{\mathbf{a}}}\;{\mathbf{x}}}}{{{\mathbf{Lo}}{{\mathbf{g}}_{\mathbf{a}}}\;{\mathbf{b}}}}\;\]

To find the value of log base 2, we first need to convert it into log base 10 which is also known as a common logarithm.

\[Log{\text{ }}base{\text{ }}2{\text{ }}of{\text{ }}x = \frac{{ln\left( x \right)}}{{ln\left( 2 \right)}}\]

 

Now You might be wondering What Common Logarithmic Function is?

  • Common Logarithmic Function or Common logarithm is the logarithm with base equal to 10.

  • It is also known as the decimal logarithm because of its base.

  • The common logarithm of x is denoted as log x.

  • Example: log 100 = 2 (Since 102= 100).

 

How to Calculate Log Base 2?

This is how to find log base 2 -

  • According to the log rule,

 

Log Rule - 

\[log_{b}(x) = y\]

\[b^{y} = x\]

 

  •  Suppose we have a question, log216 = x

  • Using the log rule,

  • 2x= 16

  • We know that 16 in powers of 2 can be written as (2×2×2×2 =16) ,2x=24

  • Therefore, x is equal to 4.

 

Questions to be Solved –

Question 1) Calculate the value of log base 2 of 64.

Solution) Here, 

X= 64

Using the formula,

\[Log{\text{ }}base{\text{ }}2{\text{ }}of{\text{ }}X = \frac{{ln\left( {64} \right)}}{{ln\left( 2 \right)}} = 6\].

Log base 2 of 64 =\[\frac{{ln\left( {64} \right)}}{{ln\left( 2 \right)}} = 6\].

Therefore, Log base 2 of 64 = 6

 

Question 2) Find the value of log2(2).

Solution) To find the value of log2(2) we will use the basic identity rule,

\[lo{g_b}\left( b \right){\text{ }} = {\text{ }}1,\].

Therefore, log2(2) = 1.

 

Question 3) What is the value of log 2 base 10?

Solution) The value of log 2 base 10 can be calculated by the rule,

\[Lo{g_a}\left( b \right){\text{ }} = \frac{{\log b}}{{\log a}}\].

\[Lo{g_{10}}\left( 2 \right){\text{ }} = \frac{{\log 2}}{{\log 10}}\; = {\text{ }}0.3010\].

Therefore, the value of log 2 base 10 = 0.3010.

 

Question 4) What is the value of log 10 base 2?

Solution) The value of log 10 base 2 can be calculated by the rule,

\[Lo{g_b}\left( a \right){\text{ }} = \frac{{\log b}}{{\log a}}\].

\[Lo{g_2}\left( {10} \right){\text{ }} = \frac{{\log 10}}{{\log 2}}\; = {\text{ 3}}{\text{.3 = 2}}\].

Therefore, the value of log 10 base 2 = 3.32.

 

Uses of Logarithms in Everyday Life

  • Earthquakes are recorded on seismographs and the amplitude is recorded on the Ritcher scale. Logarithmic values are used to comprehend these values

  • It is also used in determining the pH value of any substance

  • logarithms are used in measuring the sound intensity. Generally, sound intensity is measured by loudness which in turn is measured using logarithms

  • They are also used in measuring complex values.

 

How to improve Scores in the Logarithm Chapter

Logarithm is just the opposite of expressing a number to the power of a digit. Many students face difficulty with this subject as they have to think and solve the problems in reverse. Following are some tips to improve your scores in logarithms:

  • Understand that logarithm is an inverse expression of powers or exponents. All you have to do is solve them inversely

  • Byheart learn all the laws of the logarithm and know what would be the end result for a particular problem if they solve it with the help of a formula

  • Understanding the end result can be done by understanding the formula you apply to solve a problem. When you apply a formula that has the answer, you will get to know the end result

  • Practice as many problems as you can with different logarithmic values

  • Refer to the previous year questions to know the exam pattern, types of questions asked in the exam and assess the depth of the questions asked by the examiner.

  • Any doubts can be clarified with your subject teacher or can be clarified from an online learning website like Vedantu.

FAQs on Log base 2

1. What do you mean by log 2?

A logarithm is an inverse expression to the number expressed as the power of some “x” digit. They are an alternate way of writing exponents. The problems related to logarithms can be solved by logarithmic laws like product law, quotient rule, power rule etc, to know more about these laws please visit the above article. Following is the definition of log 2 value:


In Mathematics log 2 is equal to log (2, x). It represents the logarithmic value of x with base equal to 2.

2. How to find log base 2 on a calculator?

Logarithms are an alternate way to express the exponents of a number. It is just the opposite way to write a number that has been written in exponential form. Any problem related to logarithms can be solved with the help of standard logarithmic formulas and laws. For example, product rule, quotient rule, power rule etc., all we have to do is recall the suitable formula, apply it to the given problem and solve it. Following is the explanation to calculate the value of log base 2 without the help of a calculator:


Calculating logarithm with base 2 is an easy task on a calculator. For example, you want to calculate the logarithm base 2 of 8, then these steps show how to find log base 2.

3. What is the value of log 2 Base 2?

Logarithms are used to express the exponents in an alternative way. Any problem related to the logarithms is solved in the inverse process of solving the exponents. They can be solved with certain logarithmic formulas and laws like the product rule, exponent rule, quotient rule. These are standard throughout all the problems. Students are recommended to remember them and recall the exact formula or rule needed to solve a problem and simplify it. To know the suitable formula to be used exactly, one should solve as many practice problems as they can or refer to previously solved logarithmic problems. Following is the explanation of the value of log 2 base:


The value of log 2 base 2 is equal to 1.

4. How to calculate log base 2 without a calculator?

According to the log rule, this is how to calculate log base 2.

According to the log rule, this is how to calculate log base 2.

Suppose we have a question, log216 = x

Using the log rule,

2x = 16


We know that 16 in powers of 2 can be written as (2×2×2×2 =16)

2x =24


Therefore, x is equal to 4.

5. What are the rules or laws of a logarithm?

logarithm is the opposite of a number raised to its power. Any logarithmic value is governed by the 7 laws of logarithms. They are:

  • The product law of logarithm defines that the logarithmic product of two numbers is the sum of the factors of the logarithms

  • The quotient law states that the logarithm of the ratio of two quantities is the logarithm of difference between the denominator and the numerator

  • The power rule states that the logarithm of the exponent is the logarithm of exponent times of the base.

  • The zero rule states that the log base 1 is equal to 0 if b is greater than 0 and b is not equal to 1

  • The identity rule states that the logarithm of the number inside the parenthesis is the same as the base and the whole is equal to 1. “B” must be greater than zero.